Protractor-gage.



PATENTED JUNE 13, 1905.

R. HEDDLE.

PROTRAGTOR GAGE.

APPLIUATION FILED 1311.3,1905` IIII'IIIU Witwe/oom vided with scale-marks STATES Patented June 13, 1905.

PATENT OEETCE.

- I DROTRACTOR-GAGE.

SPECIFICATION forming part of Letters Patent No. 792,212, dated J' une 13, 190,5.

I Application led April 3, 1905. Serial No. 253,601.

[o f//ZZ whom, it 77am/ concern:

Be it known that I, ROBERT HEDDLE, a subject of the King of Great Britain,residing at Nelson, in the county of Kootenay, Dominion of Canada, have invented certain new and useful Improvements in Protractor-Gages; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to protractor-gages, and the principal object of the same is to provide a protractor attachment to be applied to an ordinary steel square and which can be readily adjusted for finding angles, diagonals for laying out stairs, circles, polygons, triangles, and other geometrie figures.

Another object is to provide a device of this character which can be quickly and accurately adjusted at different points upon opposite sides of an ordinary steel square to provide a gage for the purposes referred to.

These and other objects are attained by means of the construction illustrated in the accompanying drawings, in which- Figure 1 is a plan view of a protractor-gage made in accordance with my invention and applied to an ordinary steel square. Fig. 2 is an edge view of the same. Fig. 3 is a plan View of the protractor-gage when used to lay out angles; and Fig. 4 is a detail sectional view, taken through one end of the gage-bars and through the fastening-screw for securing said device together at opposite sides of the square.

Referring to the drawings for a more particular description of my invention, the numeral 1 denotes an ordinary steel square, having upon its opposite faces the usual scalemarks 2, one side being divided into siX- teenths and the other side into twelfths of an inch, as is the usual practice. The gage-bars 3 are each provided with an opening 4 at each side of its pivotal point 5, and upon the face Y of the bar adjacent to the openings is a scale or centering mark 6. These bars are provided with right-angular flanges 7, also pro- 8, which correspond with the scale-marks upon the opposite sides of the square 1. At the ends of said bars binding-screws 9 are provided, a stud 10 rising fromione of said bars and properly threaded to accommodate the nuts 11. A spring 12 is disposed between the two gage-bars and fingers 13 project upward from the lower bar through apertures 14; at the ends of the spring and through holes 15 in the upper gage-bar. By this means the plates are spaced apart to compensate for the thickness of the steel square.

A sector-shaped gage-plate 16, provided with a scale 17 and a straight base portion 18, which lies against one edge of the square, is provided with a pivot 19, which passes through both gage-bars and through said plate. Said pivot 19 comprises a Square shank upon one member and a threaded thumb-screw passing through the opposite member and into the square portion of said screw to hold the parts in proper relative positions.

From the foregoing it will be obvious that my invention may be applied to an ordinary steel square and adjusted to the required positions for laying out and determining many geometrical problems. When used as shown in Fig. 3, the device may be usedfor laying out angles, as will be readily understood.

Various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the principle or sacriiicing any of the advantages of this invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A protractor-gage for attachment to a steel square comprising gage-bars provided lwith sight-openings, angularlybent iianges and a sector-shaped gage-plate pivoted between said bars, substantially as described.

2. A protractor-gage comprising parallel bars, each having oppositely-disposed sightopenings provided with scales, a gage-plate pivoted between said bars and provided with a curved scale and set-screws for holding said gage-bars upon opposite sides of a steel square.

3. A protractor-gage comprising parallel bars, an intermediate gageplate provided With a curved seele and pivoted between Seid In testimony whereof I have hereunto set bars7 ineens for clamping Said gage-plate at my hand in presence of two subscribing Wituny adjusted position, set-screws at the ends of said bers, spring-spacers between said bers and tingers projecting from one of said bars through apertures in the other bar, Substantially as described.

nesses.

ROBERT HEDDLE. fitnessesz E. H. STANLEY, JAMES HARGREAVES. 

